Fate of ExoMars lander hangs in the balance

[Waspie_Dwarf]

22 minutes ago, Merc14 said:

It was moving very fast when it hit.  I wonder if the parachute ripped off or was released early?  

It was released early.

[toast]

Today, Rolf Densing/ ESA Head of Missions, stated in the new magazine DER SPIEGEL that the failure was caused by a software communication problem. The altimeter of Schiaparelli provided data as planned but this data wasnt processed by Schiaparelli`s navigation system because it was switched off as it "was in the opinion" that the touchdown has been executed already. As a result, the retrorockets fired for 3 seconds ony, which was the minimum possible operation time, instead of 60 seconds. Further investigations about the software failure are in process, the final report is expected to be ready in 2 weeks.

[Merc14]

14 minutes ago, toast said:

Today, Rolf Densing/ ESA Head of Missions, stated in the new magazine DER SPIEGEL that the failure was caused by a software communication problem. The altimeter of Schiaparelli provided data as planned but this data wasnt processed by Schiaparelli`s navigation system because it was switched off as it "was in the opinion" that the touchdown has been executed already. As a result, the retrorockets fired for 3 seconds ony, which was the minimum possible operation time, instead of 60 seconds. Further investigations about the software failure are in process, the final report is expected to be ready in 2 weeks.

Some code monkey is in a heap of trouble.

[stevewinn]

Another crash and burn on Mars.

What is the success rate for intact landings on Mars?

[Derek Willis]

20 hours ago, toast said:

Today, Rolf Densing/ ESA Head of Missions, stated in the new magazine DER SPIEGEL that the failure was caused by a software communication problem. The altimeter of Schiaparelli provided data as planned but this data wasnt processed by Schiaparelli`s navigation system because it was switched off as it "was in the opinion" that the touchdown has been executed already. As a result, the retrorockets fired for 3 seconds ony, which was the minimum possible operation time, instead of 60 seconds. Further investigations about the software failure are in process, the final report is expected to be ready in 2 weeks.

Didn't someone earlier post that they hoped it wasn't another case of imperial units being mixed up with metric units? It is unbelievable how, when NASA were able to successfully land the two Viking probes forty years ago, this sort of problem could occur now.

[Waspie_Dwarf]

30 minutes ago, Derek Willis said:

It is unbelievable how, when NASA were able to successfully land the two Viking probes forty years ago, this sort of problem could occur now.

It's not unbelievable at all.

The Vikings were relatively unsophisticated. Had they landed on a rock they would have been destroyed. That was one of the reasons NASA sent two, it gave them a better chance of success. As it happens NASA got lucky and they both survived. 

Modern landers are much more sophisticated. They are increasingly able to make autonomous decisions, rather than relying on a simple timer based system to land, meaning that space agencies can actually send them to places of interest rather than picking flat, relatively uninteresting landing spots.

The downside is that with increased  complexity comes increased chances that something could go wrong... which is exactly why ESA chose to land this mission. Its main mission was as a technology demonstrator designed to test the systems which will be used to land the far more complex (and expensive) ExoMars rover in 2020.

Far better that this software glitch was discovered now than when the rover attempts to land.

[toast]

1 hour ago, Derek Willis said:

Didn't someone earlier post that they hoped it wasn't another case of imperial units being mixed up with metric units? 

We will know in 2 weeks.

[Derek Willis]

3 hours ago, Waspie_Dwarf said:

It's not unbelievable at all.

The Vikings were relatively unsophisticated. Had they landed on a rock they would have been destroyed. That was one of the reasons NASA sent two, it gave them a better chance of success. As it happens NASA got lucky and they both survived. 

Modern landers are much more sophisticated. They are increasingly able to make autonomous decisions, rather than relying on a simple timer based system to land, meaning that space agencies can actually send them to places of interest rather than picking flat, relatively uninteresting landing spots.

The downside is that with increased  complexity comes increased chances that something could go wrong... which is exactly why ESA chose to land this mission. Its main mission was as a technology demonstrator designed to test the systems which will be used to land the far more complex (and expensive) ExoMars rover in 2020.

Far better that this software glitch was discovered now than when the rover attempts to land.

So what did all that sophistication result in? A lander that failed. If a lander is given more sophistication than the highly successful Viking landers, it is only of value if it actually manages to land.

Edit: And by the way, Waspie, as usual you like to miss out facts to make your point. The Viking landers did not only have "timers" - they had a relatively sophisticated terminal descent velocity landing radar system to determine how long the retro rockets should burn for.

http://www.jpl.nasa.gov/news/fact_sheets/viking.pdf

And also, as usual, you tend not to reply to posts that point out your errors/omissions. 

Edited October 28, 2016 by Derek Willis

[Derek Willis]

1 hour ago, toast said:

We will know in 2 weeks.

I am not saying there was a mix up with imperial and metric units. The poster made the comment to suggest that human error was the reason the Schiaparelli failed - i.e. something went wrong with the programming.